.TH GPTLsetutr 3 "May, 2020" "GPTL"

.SH NAME
GPTLsetutr \- Choose a different underlying wallclock timing routine than the default (gettimeofday)

.SH SYNOPSIS
.B C/C++ Interface:
.nf
#include <gptl.h>
int GPTLsetutr (const int routine);
.fi

.B Fortran Interface:
.nf
use gptl
integer gptlsetutr (integer routine)
.fi

.SH DESCRIPTION
Sets the underlying timing routine to one of the supported values.
.B gettimeofday() 
is the default. See
.B gptl.h
(or
.B gptl.inc
for Fortran) for the list of supported underlying timing
routines. gettimeofday() is generally the slowest option. But it is
available almost everywhere.

.SH ARGUMENTS
.I routine
-- routine identifier (see gptl.h or gptl.inc for available routines)

.SH RESTRICTIONS
Any calls to this routine must be done prior to GPTLinitialize. It should be
called from an unthreaded region.

.SH RETURN VALUES
On success, this function returns 0.
On error, a negative error code is returned and a descriptive message
printed. 

.SH EXAMPLES
.nf         
.if t .ft CW

if (GPTLsetutr (GPTLmpiwtime) != 0)  /* Use MPI_Wtime() to gather wallclock stats */
  handle_error (1);

.if t .ft P
.fi

.SH SEE ALSO
.BR GPTLinitialize "(3)" 
